Insects are inspiring improved renewable energy technologies

Biomimetics is an established field in engineering. The practice draws inspiration from nature to improve models, processes and systems. We have biomimetic engineering to thank for Velcro (inspired by the way that burr seeds stick to animal hairs) and bird-safe glass, among others.

Now, engineers may have stumbled upon the next big development in renewable energy thanks to the humble dragonfly. Research has found that the shape and flexibility of dragonfly wings makes them particularly well-suited to high wind speeds.

This discovery could help to inform the design of new, miniature wind turbines capable of operating in strong winds, which traditional turbines are not capable of. While this is unlikely to be useful for traditional-scale wind turbines, it could lead to the development of small-scale turbines for low-energy applications, such as powering LED lighting.

Similarly, photovoltaic (PV) solar technology could be improved thanks to inspiration from nature, with butterflies providing the design template.

Researchers in Germany have studied a particular butterfly, the common rose, which is native to and widespread across Asia. The common rose is black, which makes it ideally suited to absorbing heat and light.

Like all butterflies, the common rose is cold blooded and needs warm ambient temperatures to keep its wing muscles from seizing up. Direct sunlight is one way that butterflies keep their temperatures up, and the structure of their wings is what his piqued the interest of researchers.

Under intense magnification, researchers found a “disordered pattern” of tiny holes of different sizes layered over each other in the wings. The research found that this arrangement was optimal for absorbing light and heat from direct sunlight.

The researchers copied this patterning on to thin-film photovoltaic cells, layering them to create a small solar cell that absorbed much more of the available sunlight than a traditional cell.

However, it’s not just dragonflies and butterflies inspiring change. Another company has taken inspiration from bumps on whale fins to reduce drag and improve wind turbine efficiency, while other researchers have looked to owls – famous for silent flight – to try to reduce noise associated with windturbines.

Taking inspiration from nature is clearly an interesting avenue for the future development of renewable technologies and sustainable living.

The energy required for heating and cooling accounts for almost half of all final energy consumption globally, with a commensurateshare of global greenhouse gas emissions. One way to combat this is to create greener, more sustainable buildings through intelligent architecture. In Zimbabwe, the Eastgate complex was modelled on termite mounds. The building uses approximately 35% less energy than comparable buildings in the city.

With so many different and diverse sources of inspiration, and almost four billion years of development, nature could prove to be the best template for engineers of the future.